 
 (defn init-ui []
   (let [stop-button (node [:button "Stop simulation"])]
+    (set-attr! stop-button :disabled)
     (listen! stop-button :click stop-simulation!)
     (append! (sel1 :#stop-button-div) stop-button) )
   (add-test "Test 1" {:x 275 :y 450 :theta 0})

                                              (if (time-for-control-tick?)
                                                (get-new-robot-velocity sensed-color)
                                                robot-velocity )
                                              tick-time ))  ) ) ) )



(defn add-test [name start-position]
  (let [button (node [:button name])]
    (listen! button :click #(do
                              (disable-start-test-buttons)
                              (simulate start-position) ))
    (append! (sel1 :#test-start-button-div) (node [:div button])) ) )

(let [last-tick-time (atom 0)]
